Sky's the limit, as far as I know. Level 284 sounds a little silly (character editor, perhaps?), to even me, who taught every character every spell (plus no RIPs, low age, etc.):And that took awhile for those levels.
On tangent, in Bard's Tale III on the Apple, your hit points display capped at 9999, although you could gain more than that (take damage and it would stay at 9999). I discovered this becuase you could, before the final trip to Malefia, return to the old man and all of the God's items, but with one newly created character, and receive over and over again the bonus experience for finding each item.
- John
http://www.tk421.net/wizardry/